NED Abstract

Copyright by American Astronomical Society.
Reproduced by permission
1989AJ.....98.1175M
THE SOUTHERN SUPERCLUSTER
SHYAMAL MITRA
Department of Astronomy, University of Texas, Austin, Texas 78712
Received 20 April 1989; revised 1 June 1989
ABSTRACT
The Southern Supercluster is the closest supercluster to the Local
Supercluster. The densest region of this supercluster lies between
supergalactic longitudes 200^deg^ and 310^deg^ and supergalactic latitudes
- 38^deg^ to -45^deg^, which correspond to right ascensions of 2 to 6 hr
and declinations of + 5^deg^ to -69^deg^. From the contour maps made of
galaxies from the Second Reference Catalogue of Bright Galaxies (RC2), two
regions, A (180^deg^ <= L <= 320^deg^, -30^deg^ >= B >= -50^deg^) and B
(260^deg^ <= L <= 360^deg^, 0^deg^ >= B >= -30^deg^) were delineated for
detailed study. Galaxies from five catalogs were compiled and the basic
parameters, diameters and axis ratios, were reduced to the RC2 system.
Magnitudes measured for 105 galaxies, most of them new, are presented. The
magnitudes for other galaxies were obtained from the RC3 (in preparation).
The radial velocities were culled from the literature. A self-consistent
distance scale was established using tertiary distance indicators-the
luminosity index {LAMBDA}_c_, and the maximum rotation velocity log V_m_
obtained from H I linewidths. The distance moduli were obtained using
parameters log D_0_ and B^0^_T_. The distance moduli derived from the
central velocity dispersion of early-type galaxies, diameters of inner
rings, and the method of "sosie" galaxies were obtained from other
catalogs. A database was assembled containing several parameters like log
D, B^0^_T_, mu, V, etc. A statistical study of their distribution was made
and a measure of their completeness estimated. It was shown for galaxies
brighter than 14.0 mag that the probability that this areal distribution
could have arisen by chance was less than 10^-3^. Several maps were
constructed to investigate the structure of the supercluster in three
dimensions using the positional coordinates and a distance estimate from
the radial velocity. The extent, size, and shape of the super-cluster were
determined. The supercluster lies within the velocity range 560-2240 km/s
and has a velocity dispersion of 345 km/s. It is 41 Mpc along its longest
dimension and is at a mean distance of 20 Mpc. Fifteen groups belonging to
the supercluster were identified. The mass, luminosity, and mass-to-light
ratio of the groups were computed. The mean mass-to-light ratio was 100h
(h=H/100). The total luminosity of the supercluster was estimated to be 2.4
x 10^12^h^-2^ L_sun_ after making corrections for incompleteness. The total
mass of the supercluster was estimated to be 2.4 x 10^12^h^-2^ L_sun_. The
Southern Supercluster is comparable to the Coma and Hercules superclusters
in terms of mass and luminosity. Even though the Southern Supercluster is
the nearest supercluster to the Local Supercluster, the two are not
physically linked. However, there seems to be a tenuous connection between
the Southern Supercluster and the Perseus Supercluster.